摘要:

APhysalopteralarva is described from the body cavity of the earwig,Labidura reparia(Pallas).

ISSN:1923-4287    

DOI:10.1139/cjr48d-015

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

Cameronia biovatagen. et sp. nov. is described fromGryllotalpa africanaBeauv. This new genus can be differentiated from the genusBinemaTrav., 1925, the only genus in the subfamily Thelastomatinae to which it shows some resemblance, by the position of the vulva, which is much posterior in the former, and by its characteristic eggs, which are without polar filaments and are laid in pairs, both the eggs losing their separate identity by fusing with each other along their flattened surfaces, slightly asymmetrically and in a constant and typical pattern.

ISSN:1923-4287    

DOI:10.1139/cjr48d-016

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

The distribution and incidence of the following species of helminths from speckled trout in lakes and rivers of the Laurentide Park are recorded:Crepidostomum cooperi,C.farionis,Phyllodistomum lachancei,Eubothrium salvelini, diphyllobothriid larvae,Ligula intestinalis,Proteocephalus parallactics, proteocephalid larva sp. inq.,Rhabdochona laurentiana,Metabronema canadense,Agamospirurasp. inq.,Echinorhynchus lateralis. The sampling includes 42 lakes and streams from seven different drainage systems. The most commonly found species are:Metabronema canadense,Crepidostomum cooperi,Eubothrium salvelini, andEchinorhynchus lateralis; these occur in all seven drainage systems. The other helminths vary in their distribution and incidence.

ISSN:1923-4287    

DOI:10.1139/cjr48d-017

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

The polychaete,Myxicola infundibulum, contains a very large nerve fiber that runs throughout the nerve cord and gives off peripheral branches to the longitudinal muscles. Movements of the animal are quick synergic contractions of the whole body and slower metachronous locomotory movements. Injury to the giant axon without interrupting the rest of the nerve cord blocks the passage of the quick contraction but not of slower locomotory waves. It is concluded that the quick end-to-end shortening is intermediated by the giant axon and that slow waves of movement depend upon transmission through short segmentally linked neurones. Traction of one segment on another is not effective in transmitting either type of movement. The giant fiber response is of an all-or-none nature. Repetitive stimuli lead to summation of muscular contractions. The axon conducts in either direction during the natural life of the animal. The nature of the effective stimuli, the simplicity of the neuronal arrangement involved, and the character of the synergic response are discussed in terms of their survival value to the species.

ISSN:1923-4287    

DOI:10.1139/cjr48d-018

出版商:NRC Research Press    

年代:1948

数据来源: NRC